[ They're a family. It's them, not him, never him with River. The one life they could never have together, to be an actual family. He tries very hard not to think about it, because if he does, he won't be able to stop. He'll also be of no use to River when she needs him most. ]

River Song can't? I don't believe it. You can. You can, you must, you will. We have to leave, you don't belong with them. Not now, not here.

[ He tugs her hand closer, cradling it between both of his. ]

I'm real, River. We are, together.

[ He doesn't know if this will work, he can't accurately discern how deeply trapped in the delusion she is. This may mean nothing to her, she may push him away, but he has to try, he has to anchor her to something real.

Still holding her hand, he shifts carefully, leaning in close to kiss her. He is real, what's between them is real and alive, right now, and it's all that matters until they can get out of this room. ]